1、tests. Over the lifetime of the study, 176 of the 997 participants developed Alzheimersdisease. However, those with the highest score on the personality test40 points or abovehad an 89% lower chance of developing the debilitating condition than participants who received 28 points orlower. These are
2、people who control impulses, and tend to follow norms and roles,Wilson told NewScientist. Previous studies suggest that exercise and intellectual stimulation can decrease the risk of Alzheimerdisease. But the link between self-discipline and a reduced risk of the illness remained strong even after r
3、esearchers discounted these factors from theirstudy. Subjects still had a 54% lower chance of developing thecondition. Exactly why conscientiousness should have an impact on Alzheimers risk remains unclear, saysWilson. He notes that brain autopsies conducted on 324 of the studys participants failed
4、to resolve themystery. Earlier work has linked the presence of plaques and protein tangles within the brain toAlzheimer. Yet, in general, the brains of those who scored highly on the conscientiousness test had as many plaques and protein tangles as those of subjects who scoredlower. Wilson suggests
5、that more careful and conscientious individuals may have more active frontal brain regions, an area that is responsible for decision-making andplanning. Increased activity in this region may perhaps compensate for a decline in function in other brain regions, hespeculates. Based on the new findings,
6、 doctors could perhaps consider certain patients at greater risk of dementia, says Ross Andel at the University of South Florida,US. This is a study about identifying people at risk,hesays. How did the study evaluate every participants sense of responsibility?A Through a 12-yearobservation. B On a n
7、eurologicalexamination. C By a cognitivetest. D By asking a group ofquestions.【正确答案】 ：D 【本题分数】：1.0分第2题Previous studies suggest A links between physical exercises andAlzheimer. B links between brain plaque andAlzheimer. C links between brain autopsies andAlzheimer. D links between self-discipline and
8、Alzheimer.B 1.0分第3题Which one of the following is NOT true about Robert Wilson at Rush University?A He and his co-workers followed 997 healthy Catholic nuns, priests and Christian brothers within 12years. B He hasnt yet found out the underlying reasons why conscientiousness has an impact on Alzheimer
9、risk. C He suggests that people with more active frontal brain regions are more careful andconscientious. D He thinks that increased activity in frontal brain regions may compensate for a decline in function in other brainregions.C 1.0分第4题This study aims to A help Catholic nuns and priests fight aga
10、instAlzheimer. B explore the possible causes of dementiarisk. C find out who are at risk of developing a form ofdementia. D determine the effects of the presence of brainplaques.1.0分第5题According to the study, which one of the personalities below is more closely related to Alzheimers disease?AScrupul
11、ousness. BOptimism. CResponsibleness. DSpontaneousness.1.0分第6题The linear flight formations of migratory birds are calledechelons. The V and the J structures are typical and are the most readily recognized flock echelons, but other variations alsooccur. Studies of several species have shown that a tr
12、ue V-shaped echelon is, in fact, less common than a J formationis. There are two well-supported and complementary explanations for why birds fly information. One is to conserve energy by taking advantage of the upward vortex fields created by the wings of the birds infront. The other is to facilitat
13、e orientation and communication among thebirds. These explanations are not mutually exclusive, and both have been backed by a variety ofstudies. The relative importance of each undoubtedly shifts as various factors, such as the season of the year or the purpose of individual flights,change. During l
14、ocal feeding flights, for example, energy conservation is probably much less important than careful orientation and collision avoidanceare. During long-distance migration, orientation and communication remain necessary, but there is also much to be gained for each bird in the flock by optimizing its
15、 position to conserveenergy. Fluid dynamics and energy wave configuration calculations have been used to test predictions of where birds should position themselves in relation to others to conserve the most energy as they travel through theair. Analyses of flock formations using photography have mea
16、sured bird positions and found them to almost always be located such that they gain some energeticadvantage. The animals are not very often in the expected optimal location, however, indicating that other factors also influence position in theformation. Knowledge of birds visual axes, blind spotsand
17、 field of vision has allowed researchers to pinpoint the best locations for birds within a flock to maintain optimal visualpositioning. Actual positions of the animals are usually positively related to these predictions but are, again, not alwaysoptimal. Studies have categorized the positions of bir
18、ds and found that some individuals take positions that are most closely predicted to satisfy the energy conservation hypothesis;others are in better visual contact positions;and still others are not apparently responding to either benefit or are in a position that should gain some advantage from bot
19、hbenefits. The leaders of formations change from time to time, but the causes, frequency and characteristics of these changes have not yet beendetermined. Sustained observation from the ground of flocks covering great distances in the air is verydifficult. There are plenty of intuitive predictions a
20、bout leader choice that quickly come to mind relative to the age, experience, sex, condition and social status of the leaders, but researchers have not figured out how to overcome the prohibitive logistic issues to testthem. Some scientists have trained birds to fly in formation with small aircraft;
21、perhaps their experiences will yield opportunities to test theseideas. Migratory birds fly in formation to A conserveenergy. B helporientation. C facilitatecommunication. D AllAbove.1.0分第7题The word eachin the 5th sentence of the second paragraph refers to Aformation. Bstudy. Cfactor. Dexplanation.1.
22、0分第8题How do the researchers test predictions of where birds should position themselves in their echelon to conserve energy?A Using the energy conservation hypothesis to categorize the positions ofbirds. B Using fluid dynamics and energy wave configurationcalculations. C Using photography to analyze
23、various flockformations. D Using knowledge of birdsand field ofvision.1.0分第9题Why do echelon leaders change sometimes?A It can help optimizeorientation. B Birds can better avoidcollision. C The reason is stillunclear. D Birds cant determine oneleader.1.0分第10题What makes sustained observation of flock
24、formations very difficult?A The characteristics of echelonchanges. B Lack in hands andequipment. C Too many intuitivepredictions. D Too many factors involved inechelons.1.0分第11题Letting computer viruses loose on a quarantined computer and recording their pattern of activity could lead to a better way
25、 of spotting them in the wild. A prototype system developed at the University of Michigan uses the fingerprintof virus activity to identify them more effectively than existing anti-virussoftware. The designers of programs that damage, take over or steal data from computerscalled malwareare locked in
26、 an arms race with companies that make anti-virus （AV） software to prevent and fix malwaredamage. Conventional AV software looks for suspicious behavior and then tries to determine whats causingit. It does this by looking for virus signatureschunks of computer code from knownviruses. But identifying previously unknown malware is difficult, and keeping track of different variants of existing viruses makes itharder. For example, a virus called Agobot has split into more than 580 variants since its release in2002. In tests, Michael Bailey and colleagues at the Univ
